Method of dispensing biosensors

ABSTRACT

A storage cartridge for dispensing biosensors used in the determination of an analyte in body fluid comprises a hollow body for housing a stack of biosensors having an open top, a flexible conveying member disposed over the open top of the body, the flexible conveying member having an aperture formed therein for receiving a biosensor from the stack of biosensors, a plate adapted to press the sliding conveying member against the open top to form a substantially moisture-impervious seal around the open top of the body and to permit the conveying member to slide between the plate and the open top, and means for biasing the stack of biosensors towards the open top.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/382,786 filed Mar. 7, 2003, which claims priority to ProvisionalApplication No. 60/364,848 filed on Mar. 18, 2002, both of which areincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to blood glucose monitoringsystems for determining the concentration of glucose in blood, and moreparticularly, to a storage cartridge for dispensing biosensors for usewith blood glucose monitoring systems.

BACKGROUND OF THE INVENTION

It is often necessary to quickly obtain a sample of blood and perform ananalysis of the blood sample. One example of a need for obtaining asample of blood is in connection with a blood glucose monitoring system,which a user must frequently use to monitor the user's blood glucoselevel.

Those who have irregular blood glucose concentration levels aremedically required to regularly self-monitor their blood glucoseconcentration level. An irregular blood glucose level can be brought onby a variety of reasons including illness such as diabetes. The purposeof monitoring the blood glucose concentration level is to determine theblood glucose concentration level and then to take corrective action,based upon whether the level is too high or too low, to bring the levelback within a normal range. The failure to take corrective action canhave serious implications. When blood glucose levels drop too low—acondition known as hypoglycemia—a person can become nervous, shaky andconfused. That person's judgment may become impaired and that person mayeventually pass out. A person can also become very ill if their bloodglucose level becomes too high—a condition known as hyperglycemia. Bothconditions, hypoglycemia and hyperglycemia, are potentiallylife-threatening emergencies.

One method of monitoring a person's blood glucose level is with aportable, hand-held blood glucose testing device. The portable nature ofthese devices enables the users to conveniently test their blood glucoselevels wherever the user may be. The glucose testing device includes abiosensor to harvest the blood for analysis. One type of biosensor isthe electrochemical biosensor. The electrochemical biosensor includes aregent designed to react with glucose in the blood to create anoxidation current at electrodes disposed within the electrochemicalbiosensor which is directly promotional to the users blood glucoseconcentration. Such a biosensor is described in U.S. Pat. Nos.5,120,420, 5,660,791, 5,759,364 and 5,798,031, each of which isincorporated herein in its entirety. Another type of sensor is anoptical biosensor, which incorporates a reagent designed to produce acolorimetric reaction indicative of a user's blood glucose concentrationlevel. The calorimetric reaction is then read by a spectrometerincorporated into the testing device. Such an optical biosensor isdescribed in U.S. Pat. No. 5,194,393, which is incorporated herein byreference in its entirety.

In order to check a person's blood glucose level, a drop of blood isobtained from the person's fingertip using a lancing device, and theblood is harvested using the biosensor. The biosensor, which is insertedinto a testing unit, is brought into contact with the blood drop. Thebiosensor draws the blood, via capillary action, inside the biosensorand the ensuing electrochemical reaction is measured by the test unitwhich then determines the concentration of glucose in the blood. Oncethe results of the test are displayed on a display of the test unit, thebiosensor is discarded. Each new test requires a new biosensor.

Referring now to FIGS. 1 and 2, an example of a testing device 10 and apackage 30 of biosensors 12 (“sensor pack”) are shown, respectively. Thesensor pack 30 is designed to be housed within the testing device 10.Prior to each test, a collection area 14 of an individual biosensor 12is pushed by a mechanism within the testing device 10 through itspackaging and is extended from the testing device 10 through a slot 16for harvesting a sample of blood. The testing device 10 includes aslider 18 for advancing the test tensor 12. In FIG. 1, a biosensor 12 isshown extending from the testing device 10. The collection area 14extends from the testing device 10, while a contact area, disposed atthe opposite end of the biosensor 12 shown in FIGS. 1 and 2, remainsinside the testing device 10. The contact area includes terminals thatelectrically couple the electrodes to a meter disposed within thetesting device 10 for measuring the oxidation current produced at theelectrodes by the reaction of glucose and the reagent. The test unitincludes a display 20.

Referring now to FIG. 2, biosensors 12 are shown disposed in the sensorpack 30. The sensor pack 30 is made up of a circular disk 32 having tenindividual compartments (blisters) 34 arranged radially. The disk ismade from an aluminum foil/plastic laminate which is sealed to isolatethe sensor from ambient humidity and from other sensors with a burstfoil cover 36. Each biosensor 12 is kept dry by a desiccant locatedinside a desiccant compartment 37 disposed adjacent to the compartment34.

To retrieve a sensor, a mechanism disposed within the testing device 10,such as a knife, is driven down through the burst foil into anindividual elongated compartment 34 at the end closest to the hub of thedisk 32 and then moved radially toward the perimeter of the blister 34.In doing so, the knife engages the contact area 38 (fish tail) of thesensor in that compartment. Radial travel of the knife pushes the tip ofthe sensor out through the burst foil 36 and through parts of thetesting device 10 such that the collection area 14 of the sensor 12 iscompletely out of the testing device 10 and ready to receive a fluidtest sample such as blood. For this stage, it is essential that the bondbetween the base and lid of the sensor withstand the sheer forcesgenerated when the sensor bursts out through the foil 36. This method ofproviding a sensor ready for use is more fully described in U.S. Pat.No. 5,575,403, which is incorporated herein by reference in itsentirety.

Further details of the operational and mechanical aspects of the testingdevice 10 and sensor pack 30 are more fully described in U.S. Pat. Nos.5,575,403, 5,630,986, 5,738,244, 5,810,199, 5,854,074 and 5,856,195,each of which are hereby incorporated by reference in their entireties.

A drawback associated with this flat array of testing devices is thelarge area that is occupied. The size of testing devices that internallyhouse such a flat array package constrains the size of the package(i.e., the number of sensors), thus making it difficult to increase thenumber of sensors per package. Accordingly, there exists a need for atesting system wherein the biosensor package size is independent of thetesting device.

SUMMARY OF THE INVENTION

A storage cartridge for dispensing biosensors used in the determinationof an analyte in body fluid comprises a hollow body for housing a stackof biosensors having an open top, a flexible conveying member disposedover the open top of the body, the flexible conveying member having anaperture formed therein for receiving a biosensor from the stack ofbiosensors, a plate adapted to press the sliding conveying memberagainst the open top to form a substantially moisture-impervious sealaround the open top of the body and to permit the conveying member toslide between the plate and the open top, and means for biasing thestack of biosensors towards the open top

The above summary of the present invention is not intended to representeach embodiment, or every aspect, of the present invention. Additionalfeatures and benefits of the present invention will become apparent fromthe detailed description, figures, and claims set forth below.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of a prior art testing device;

FIG. 2 is a perspective view of a prior art sensor pack having a foillid removed;

FIG. 3 is a first side view of a storage cartridge for biosensorsaccording to one embodiment of the present invention;

FIG. 4 is a second side view of a storage cartridge for biosensorsaccording to one embodiment of the present invention;

FIG. 5 is a third side view of a storage cartridge for biosensorsaccording to one embodiment of the present invention;

FIG. 6 is fourth side view of a storage cartridge for biosensorsaccording to one embodiment of the present invention;

FIG. 7 is a perspective view of a flexible sliding conveying member forthe storage cartridge for biosensors shown in FIGS. 3-6;

FIG. 8 a is a cut-away view of the storage cartridge shown in FIG. 6along dashed line 8; and

FIG. 8 b is a cut-away view along dashed line 8 of FIG. 6 of analternative embodiment of the storage cartridge.

While the invention is susceptible to various modifications andalternative forms, specific embodiments will be shown by way of examplein the drawings and will be desired in detail herein. It should beunderstood, however, that the invention is not intended to be limited tothe particular forms disclosed. Rather, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Referring now to FIG. 3, there is shown a sensor cartridge 100 forstoring a plurality of biosensors 102, such as the biosensors 12described in connection with FIGS. 1 and 2, according to one embodimentof the present invention. Also shown in FIG. 3 is a testing device 104which receives a biosensor 102 from the sensor cartridge 100 fordetermining a person's blood glucose level. The testing device 104functions similar to that of the prior art testing device 10 shown inFIG. 1. The storage cartridge 100 provides a sealed, substantiallymoisture-impervious environment for storing the plurality of biosensors102. According to one embodiment of the storage cartridge 100, theplurality of biosensors 102 are stacked, substantially one on top of thenext, as shown in FIGS. 3-6. Generally, in use, the biosensors 102 aredispensed from the storage cartridge 100 via a sealed outlet 106.

The stacked biosensors 102 are in vapor communication with a desiccantmaterial 108 disposed within the storage cartridge 100. The desiccantmaterial 108 maintains the interior of the sensor cartridge 100 at anappropriate humidity level so that the reagent material disposed withinthe biosensors 102 is not adversely affected prior to being used. Thedesiccant material 108 is in the form of a small bag, round bead ofmaterial, a hot melt, a molded shape or any other form that can bereadily disposed in the sensor cartridge 100. While the desiccantmaterial 108 shown (FIG. 3) is disposed towards the bottom of thestorage cartridge 102, the desiccant material 108 may be disposedanywhere practical within the storage cartridge 100 according toalternative embodiments of the storage cartridge 100. The amount of suchdesiccant material 108 placed within the sensor cartridge 100 will bedependent on the amount that is required to maintain the interior of thesensor cartridge 100 in a desiccated state. One type of commerciallyavailable desiccant material that can be used in one embodiment of thepresent invention is 13× synthetic molecular sieves from MultisorbTechnologies Inc. of Buffalo, N.Y., available in powder, pellet and beadforms.

The sensor cartridge 100 is made of a rigid, moisture-imperviousmaterial such as plastic. Each of the biosensors are approximately 0.50inch long (about 12.70 mm), approximately 0.03 inch thick (about 0.76mm) and approximately 0.20 inch wide (about 5.08 mm). The interior ofthe of the sensor cartridge 100 is dimensioned only slightly larger thanthe length and width of the biosensors 120 to allow the biosensors 102to move vertically within the storage cartridge (as described below) butnot side-to-side (as viewed in FIG. 3) so that the stack of thebiosensors 102 is maintained. For example, according to one embodimentof the storage cartridge 100, the storage cartridge 100 has an interiorwidth W of approximately 0.52 inch (about 13.21 mm) and an interiordepth (into the page as viewed in FIG. 3) of approximately 0.22 inch(about 5.59 mm). The interior height H is approximately 2.25 inch (about57.15 mm) for an embodiment of the storage cartridge that is adapted tohouses approximately fifty sensors. The interior height H can be variedaccording to alternative embodiments of the storage cartridge 100 toaccommodate an increased or decreased number of biosensor 102.

The sensors 102 are dispensed from the storage cartridge 100 via thesealed outlet 106 located towards the top 110 of the storage cartridge.The stack of biosensors 102 is biased upward towards the top 110 of thestorage cartridge 100 by a resilient member such as a spring 112disposed between the stack of biosensors 102 and an interior bottomsurface 114 of the storage cartridge 100.

Referring now also to FIG. 4, the top of the storage cartridge 100 issealed by a flexible, slideable conveying member 116 that is pressedagainst the top 110 of the storage cartridge 100 by a top plate 134.According to one embodiment, the conveying member 116 is made out ofpolyolefin, which includes the attributes of low moisture vaportransmission, flexibility and a lubricious surface. According to oneembodiment, the conveying member 116 protrudes from the storagecartridge 100 at the outlet 106 as well as through a second outlet 118located on the opposite side of the storage cartridge 100. The conveyingmember 116 seals outlets 106, 118 as described below. The conveyingmember 116 (FIG. 7) includes a cutout or nest 120. The nest 120 isdesigned to fit around a biosensor 102. Put another way, the nest 102receives the biosensor 102. As described in further detail below, theconveying member 116, which surrounds a biosensor 102, is pulled acrossthe top of the storage cartridge 100 (from right to left as viewed inFIG. 3) and, in turn, the biosensor 102 is pulled/dragged from thestorage cartridge 100. As shown in FIG. 7, the nest 120 is cut in theshape of a biosensor such as the biosensors 12 depicted in FIG. 2. Inother embodiments, the nest 120 is more general in shape (e.g., arectangle) to accommodate biosensors of a variety of shapes.

In operation, the user of the storage cartridge 100 and testing device104 pulls a first end 122 of the conveying member 116. Either prior tothe user's pulling or during, the spring 112, which constantly biasesthe stack of biosensors 102 upward, pushes the biosensor 102 at the topof the stack into the nest 120. This biosensor 102, within the nest 120and surrounded by the conveying member 116, is pulled along with theconveying member 116 towards the outlet 106. The flexible conveyingmember 116 is pulled around a post 124 at an approximately 90° angle. InFIGS. 3-6, the post 124 is shown disposed away from the storagecartridge 100. However, in other embodiments, the post 124 is anintegral component of the storage cartridge 100 as is shown in FIG. 6.Alternatively still, the post 124 may comprise a rounded corner of thestorage cartridge 100.

Referring now to FIG. 4, the conveying member 116 is pulled in thedirection indicated by arrow A from the storage cartridge 100 such thatthe biosensor 102 is partially protruding from the outlet 106 of thestorage cartridge 100. A leading end 130 of the biosensor 102,surrounded by the conveying member 116, is proximate the post 124. Asthe flexible conveying member 116 is pulled around the post 124, therelatively rigid biosensor 102 continues to travel in a straight line(in the direction of arrow A). A trailing end 132 of the biosensor 102,which is still within the storage cartridge 100, is still constrained toits original path by the top plate 134 of the storage cartridge 100 andthe adjacent lower biosensor 102.

Referring now to FIG. 5, the conveying member 116 is pulled in thedirection indicated by arrow A until a substantial portion of theleading end 130 of the biosensor 102 is extended beyond the post 124 andis not surrounded by the conveying member 116. The leading end 130 ofthe biosensor 102 is then forced into a mating portion 140 of thetesting device 104. As the biosensor 102 is pulled out of the storagecartridge, the spring 112 forces a biosensor 102 within the storagecartridge upward against the conveying member 116.

Referring now also to FIG. 6, the biosensor 102 is now disposed withinthe testing device and can be used in the analysis of a sample of blood.The second end 142 of the conveying member 116 is pulled back in thedirection indicated by arrow B causing the nest 120 to be brought backinside the storage cartridge 100 to receive another biosensor 102 forthe next test. As the conveying member 116 is pulled back into the testcartridge 100 and the nest 120 passes over the stack of biosensors 102,the uppermost biosensor 102 is forced upward into the nest 120 by thespring 112.

In FIGS. 3-5 the post has 124 been shown as not attached to the storagecartridge 100. In FIG. 6, the post 124 is shown as a rounded corner ofprotrusion 125 which extends outward from the cartridge 100. In otheralternative embodiments of the storage cassette 100, there is noprotrusion 125 (or post 124) and the conveying member is simply pulledaround the corner at the outlet 106 of the storage cartridge.

Referring now to FIG. 8 a there is shown a cut-away view of the storagecartridge 100 along dashed line 8 (FIG. 6). The conveying member 116 isdisposed between side-walls 150 of the storage cartridge 100 and the topplate 134. The plate 134 functions as the top of the storage cartridge100. The plate 134 is pressed down onto the conveying member 116 withsufficient pressure that a substantially moisture-impervious seal isformed between the top plate 134, the sliding conveying member 116 andthe walls 150 of the storage cartridge. According to one embodiment, thepressed thickness of the conveying member 116 is at least slightly lessthan that of the biosensor 102 to facilitate the trapping and draggingof just one biosensor out of the storage cartridge. According to oneembodiment of the present invention, a substantially constant amount ofpressure is applied by the plate 134 to the conveying member 116 and thewalls 150. A suitable fastener (e.g., screws, rivets, clamps) can beused to press the plate 134 against the conveying member 116 and walls150 as described. However, the constant pressure applied to theconveying member 116 by the plate 134 should not be so great as tounduly inhibit the sliding of conveying member 116 when pulled by a userwhen dispensing of a biosensor 102. Constructing the conveying member116 out of a lubricious material such as polyolefin, according to oneembodiment, facilitates the sliding movement of the conveying member116.

In an alternative embodiment of the storage cassette 110, the pressureapplied to the conveying member 116 and walls 150 by the plate 134 maybe temporarily reduced or eliminated during the dragging process. Insuch an embodiment, the reduced pressure may break the substantiallymoisture-impervious seal of the storage cassette 100. However, anymoisture leaking into the storage cassette 100 during the temporarybreak in the seal is absorbed by the desiccant 108 (FIG. 3). A varietyof mechanical schemes can be employed for varying the pressure appliedby the top plate 134 according to alternative embodiments of the presentinvention. For example, in one embodiment, an adjustable clamp (notshown) may be used to vary the pressure applied by the top plate 134. Inanother embodiment, screws (not shown), such screws having heads largeenough to be grasped by a user's fingers, may be used to vary thepressure applied by the top plate 134. Alternatively still, an elasticmember (not shown) may apply sufficient pressure to the top plate 134for forming the seal around the walls 150, but be elastic enough toallow the plate to lift slightly during the dragging process when abiosensor is being dispensed. In yet another alternative embodiment, awedge-type of arrangement can be employed wherein the top plate 134 isinserted into grooves (not shown) disposed within the interior of walls150 wherein the grooves direct the top plate 134 down into pressedcontact with the conveying member 116.

As shown in FIG. 8 a, according to one embodiment, the conveying member116 is disposed on flat surfaces 154 which are integrally formed inwalls 150. However, other configurations are possible according tovarious other alternative embodiments of the storage cassette 100. Forexample, the conveying member 116 is disposed directly on top of walls150 according to the alternative embodiment of the storage cartridge 100shown in FIG. 8 b.

According to one embodiment of the storage cartridge 100, the biosensors102 are arranged within the storage cartridge such that the leading end130 of the biosensor 102 (i.e., the end of the first pulled from thecartridge 100) is the contact area of an electrochemical biosensor. Asdiscussed in the background section, the contact area of the biosensor102 includes terminals which electrically couple the biosensor 102 tothe testing device 104. Dispensing the biosensors 102 in this manner isadvantageous over many prior art biosensor dispensing schemes becausethe sample collection area (i.e., disposed on the end opposite thecontact area in FIGS. 1 and 2) of the biosensor 102 never contacts orpasses through the testing device 104. This arrangement removes thepotential risk of cross-contamination in situations where the testingdevice 104 may be used by more than one patient.

According to still another alternative embodiment, the storage cartridgeis part of the testing device. In such an embodiment, the portion of thetesting device that receives the sensor is movable with respect to thestorage cartridge such that the sample collection area of the sensor isavailable to receive the sample.

Referring back to FIG. 6, the second end 142 of the conveying member 116has been shown and described as extending out of the storage cartridgethrough the second outlet 118. However, in alternative embodiments ofthe storage cartridge, the second end 142 of the conveying member 118remains within the storage cartridge 100. According to one suchembodiment, the second end is attached to a resilient member within thestorage cartridge 100 for retracting the sliding conveying member 116after a biosensor 102 has been dispensed. According to another suchembodiment, the conveying member 116 is pushed back through the firstoutlet 106 by the user. According to yet another such embodiment, amechanical apparatus such as a roller is integrated into the storagecartridge 100 for pushing or pulling the conveying member 116 back intothe storage cartridge 100.

According to still another alternative embodiment of the storagecartridge 100 implements a length of conveying member 116 having aplurality of evenly spaced-apart nests 120 formed therein. The length ofconveying member 116 is stored in the form of a roll, or is folded.After a portion of the conveying member 116 is pulled from the cartridge100 and a sensor 102 is dispensed, that portion of the conveying member116 can be torn or cut and discarded leaving a sufficient amount ofconveying member to grasp for dispensing the next cartridge.

According to other alternative embodiments of the present invention,other biasing members are used in place of a resilient member (e.g. thespring 112 shown in FIG. 3) for upwardly (as view in FIG. 3) the stackof biosensors 102. For example, in such alternative embodiments, thebiasing member may include a first magnet disposed on the interiorbottom surface 114 of the storage cartridge 100 and a second repulsivelydisposed magnet attached to the stack of biosensors 102. The stack ofsensors 102 is biased upward via electromagnetic forces that cause thefirst magnet and the second magnet to repulse (i.e., push away from)each other. In another alternative embodiment, the magnets compriseopposing ferromagnets as opposed to eletromagnets. Alternatively, acombination of electomagnets and ferromagnets may be used.

In other alternative embodiments, the biasing member may comprise apneumatic system wherein a compressed gas is used to upwardly bias thestack of biosensors 102. According to one alternative embodiment, thestack of biosensors 102 are disposed on the top-side of a piston in apiston-cylinder arrangement, wherein the cartridge 100 severs as thecylinder. A compressed gas disposed in the cylinder, beneath the piston,biases the stack of test sensors 102 towards the top 110 of thecartridge 100.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and herein described in detail. It should beunderstood, however, that it is not intended to limit the invention tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

1-10. (canceled)
 11. A method for dispensing a biosensor used in thedetermination of an analyte in a body fluid from a biosensor storagecartridge, the method comprising: providing a plurality of stackedbiosensors within a hollow body of the storage cartridge, the hollowbody being closed at a first end and open at a second end; disposing aflexible conveying member over the open second end, the conveying memberforming at least one aperture therein; applying pressure to theconveying member at the open second end to form a substantiallymoisture-impervious seal over the open second end; biasing thebiosensors stacked within the cartridge towards the sealed second end;receiving a biosensor from the stack of biosensors in the at least oneaperture formed in the conveying member; and pulling a portion of theconveying member from the cartridge such that the biosensor received inthe at least one aperture is pulled from the cartridge, the flexibleconveying member being sufficiently flexible to assist in removing thebiosensor therefrom.
 12. The method of claim 11 wherein pulling furthercomprises reducing the pressure applied to the conveying member.
 13. Themethod of claim 11 wherein the conveying member comprises polyolefin.14. (canceled)
 15. The method of claim 11 wherein the conveying memberis made out of a material having a lubricious surface.
 16. The method ofclaim 11 wherein the flexible conveying member has a low moisture vaportransmission rate.
 17. The method of claim 11 wherein biasing furthercomprises biasing the stack of biosensors towards the sealed second endwith a resilient member disposed between the stack of biosensors and thefirst end of the hollow cartridge.
 18. The method of claim 17 whereinthe resilient member is a spring.
 19. The method of claim 11 whereineach of the biosensors has a contact area for interfacing with a testingunit and a collection area for receiving the body fluid, the methodfurther comprising stacking the biosensors within the hollow body suchthat each biosensor is dispensed contact area first.
 20. The method ofclaim 19 further comprising measuring a reaction between a reagentdisposed in the biosensor and the analyte in the received body fluid.21. The method of claim 20 further comprising determining theconcentration of the analyte in the body fluid.
 22. The method of claim21 further comprising disposing a desiccant within the hollow body.23-36. (canceled)
 37. A method for dispensing a biosensor used in thedetermination of an analyte in a body fluid from a biosensor storagecartridge, the method comprising: providing a plurality of stackedbiosensors within a hollow body of the storage cartridge, the hollowbody being closed at a first end, open at a second end and having twosides; disposing a flexible conveying member over the open second endand generally within the sides of the hollow body, the conveying memberforming at least one aperture therein; applying pressure to theconveying member to form a seal over the open second end; biasing thebiosensors stacked within the cartridge towards the sealed second end;receiving a biosensor from the stack of biosensors in the at least oneaperture formed in the conveying member; pulling a portion of theconveying member from the cartridge such that the biosensor received inthe at least one aperture is pulled from the cartridge; and removing thebiosensor from the flexible conveying member, the flexible conveyingmember being sufficiently flexible to assist in removing the biosensortherefrom.
 38. The method of claim 37 wherein pulling further comprisesreducing the pressure applied to the conveying member.
 39. The method ofclaim 37 wherein the conveying member comprises polyolefin.
 40. Themethod of claim 37 wherein biasing further comprises biasing the stackof biosensors towards the sealed second end with a resilient memberdisposed between the stack of biosensors and the first end of the hollowcartridge.
 41. The method of claim 37 wherein each of the biosensors hasa contact area for interfacing with a testing unit and a collection areafor receiving the body fluid, wherein removing the biosensor from theconveying member is performed by dispensing the contact area of thebiosensor first.
 42. The method of claim 37 wherein the hollow bodyincludes a desiccant.